New device for the storage and use of hydraulic and/or pneumatic power, particularly for operation of submerged well heads

ABSTRACT

Device for energizing operating members of a submerged installation such as a well head, comprising storage means for a pressurized working fluid, circuit means in communication with said storage means for actuating said operating members by action of the working fluid passing therethrough, and means for pressurizing the working fluid in said storage means, actuated by a pressurized auxiliary fluid such as the drilling fluid.

United States Patent [191 Harbonn July 3, 1973 [541 NEw DEvICE FOR Tm; STOR GE AND USE 3,186,486 6/1965 Rhodes et a]. 166/.6

or HYDRAULIC AND/OR PNEUMATIC POWER PARTICULARLY FOR OPERATION 3:496:99) 2/1970 Rowley 0F SUBMERGED WELL HEADS 3,405,387 10/1968 Koomey et al 166/.5 x

Inventor: Jacques Harbonn, Jouars Ponchartrain, France Institut Francais du Petrole des Carburants et Lubrifiants, France Filed: Feb. 17, 1971 Appl. N0.: 116,134

Assignee:

Foreign Application Priority Data Feb. 25, 1970 France 7006859 US. Cl. 166/.5, 175/5 Field of Search 166/5, .6; 175/5-10; 60/51 References Cited UNITED STATES PATENTS 8/1967 Hubby 166/.5

Primary Examiner.loseph H. McGlynn Assistant Examiner-Richard E. Favreau Attorney-Craig, Antonelli, Stewart & Hill [57] ABSTRACT Device for energizing operating members of a submerged installation such as a well head, comprising storage means for a pressurized working fluid, circuit means in communication with said storage means for actuating said operating members by action of the working fluid passing therethrough, and means for pressurizing the working fluid in said storage means, actuated by a pressurized auxiliary fluid such as the drilling fluid.

7 Claims, 1 Drawing Figure PATEN TED JUL 3 I973 INVENTOR TACQUES HARBONN BY Craig, Antonelh, SEeuorl. Hill ATTORNEYS NEW DEVICE FOR THE STORAGE AND USE OF HYDRAULIC AND/OR PNEUMATIC POWER, PARTICULARLY FOR OPERATION OF SUBMERGED WELL HEADS It is an object of this invention to provide a new device for the storage and use of hydraulic and/or pneumatic power, particularly adapted as equipment for operation of submerged well heads. During drilling operations, particularly underwater drilling, members of the well head equipment such as valves, well sealing block and the like, have to be operated. In most cases these members are controlled through hydraulic means, and, in the case of underwater drillings, the pressurized fluid required for controlling said members is provided by a fluid pressurizing equipment on board of the surface installation from which is conducted the drilling operation.

Such an arrangement involves hydraulic pipes connecting the surface installation to the members to be operated. By experience it became apparent that these hydraulic pipes are not only of a high cost, resulting in a significant investment, but are also responsible of troubles for the user. In fact these hydraulic pipes require a permanent maintenance and checking as well as the use of suitable devices for their connection to the well heads. Furthermore, in addition to the power required for actuating the well head members, the surface installation must provide an additional power in order to compensate for the pressure losses through the pipes connecting the well head to the surface installation, these pressure losses being in proportion of the pipe length.

Attempts have been made to avoid the presence or reduce the number of these hydraulic pipes which encumber the water body between the surface installation and the well head. Devices already known in the art may be used for reducing the number of hydraulic pipes by means of a particular arrangement of the control members such as hydraulic and/or pneumatic distributors forming part of the well head equipment, but the above-mentioned drawbacks are not completely avoided.

In other devices it has been proposed to provide the drilling well head with its own hydraulic power source. Such devices have the advantage of avoiding the necessity of control hydraulic pipes connecting the main installation to the well head, but they are replaced by at least one electric cable for feeding with electric power, from the surface, a motor which actuates the device for pressurizing the hydraulic fluid.

The presence of this cable has substantially the same disadvantages as that of the hydraulic pipes (high cost, need for a maintenance and checking service, cumbersomeness in the water body, handling operations etc It is an object of the present invention to provide a new device for the storage and use of hydraulic power, whereby the above-mentioned drawbacks can be avoided and in particular making possible to limit the connections between the surface installation and the well head to the drilling fluid circulation lines, any other connection line with the exception, of course, of the drill string, being needless.

These and other objects and advantages, as will be apparent from the following description, are achieved by using a device for the storage and use of hydraulic and/or pneumatic power, comprising a storage tank for a hydraulic or pneumatic fluid, means for pressurizing said fluid, means for storing and using said pressurized fluid, said means for pressurizing the hydraulic fluid being actuated through a pressurized auxiliary fluid.

One of the advantages of the present invention is to make possible the omission of all connections between the well head and the surface installation other than the drill string and the drilling fluid circulation lines.

Another advantage of the present invention is to suppress from the surface installation any power generating device required only for the actuation of the drilling well head members.

The invention will be better understood and further advantages made apparent from the following description of a non-limitative embodiment of the device of this invention, illustrated by the accompanying drawmg.

This description more particularly contemplates, in a non-limitative manner, the use of the device according to the invention in association and submerged with an oil well head.

In the drawing the well head is not shown and reference l designates an oil and air accumulator of any known type, e.g., with a piston or a deformable membrane. This accumulator is connected, through a pipe 2 and valves 3a, 3b, to operating hydraulic devices 40, 4b, respectively, which actuate members, not shown, forming part of the well head equipment, such as blow out preventers, valves etc The control of valves 30, 311, may be achieved, from the surface installation, through any known means, particularly through remote control means (not shown) associated to the well head, the remote control being, for example performed by means of acoustic waves transmitted from the surface installation.

The accompanying drawing only shows two operating devices 4a, 4b and their respective control valves 3a, 3b, but this number is by no way limitative and depends exclusively on the member of members of the well head equipment to be controlled. These operating devices are connected through a pipe 5 to the tank 6 of the hydraulic circuit. A non-return valve 7 allows the hydraulic fluid to flow in a single direction, from the operating device to the tank 6. A pipe 8 connects the tank 6 to the accumulator 1 through a non-return valve 9 preventing the discharge of the accumulator 1 into the tank 6. In the tank 6 is provided a floating piston 10, slidable in the body 1 1 of tank 6, which tightly separates the upper part from the lower part of said tank 6. This piston may come into abutment against a shoulder 12 at the upper part of tank 6.

This tank 6 is surrounded with a cylindrical chamber 13 wherein is slidably mounted a piston 14 having its face, on the side of tank 6, provided with a push-rod 15. A spring 16 maintains piston 14 to its upper position in chamber 13.

At its lower part, chamber 13 communicates with the external medium 17 through one or more orifices 18. In the considered case, this external medium is sea water wherein the device is submerged.

At its upper part, chamber 13 communicates, on the one hand, with the external medium 17 through a discharge pipe 19 and a valve 20, and, on the other hand, with a pipe 21 through a pipe 22 and a valve 23.

Valves 20 and 23 are, for example, hydraulic valves controlled through one-stroke jacks 26 and 27, against the action of repelling devices. Jacks 26 and 27 are respectively fed through pipes 24a and 24b, connected to pipe 2.

According to the invention, pipe 21 is connected to a duct 25 for the circulation of the drilling muds. This pipe may be one of the two pipes called in the art choke line and kill line.

Accordingly, in view of the fact that, during the drilling operations, particularly at sea, the well head is necessarily connected to the surface installation through pipes for circulation of the drilling fluid, the pressure of said drilling fluid is used, according to the invention for operating the hydraulic power generating device in a manner which will be stated hereinafter. By this way, there is avoided a connection between the well head and the surface installation through a cable or a special pipe in order to provide the power required for operating the well head members.

The device is operated as follows:

It is assumed that the pressure in accumulator 1 has a value P (Operative pressure in the range between a minimum value P min and a maximum value P max) greater than the pressure P prevailing in tank 6.

The device is thus in the state shown in FIG. 1, all the valves such as 3a, 312 being closed.

When it is desired to actuate a member of the well head, there is transmitted, through a control device (not shown), an order which produces the opening of the valve feeding the corresponding operating device. For example the valve 3a is opened and the hydraulic fluid flows, thereby actuating the operating device 4 a, from accumulator l to tank 6 through pipe 2, valve 3 0, operating device 4 a, pipe 5 and non-return. valve 7.

The volume of hydraulic fluid contained in tank 6 increases and piston 10 rises while expelling through orifice 18, the external fluid, i.e., the water surrounding the device, contained in the upper portion of tank 6. The actuation of the members is continued until piston 10 comes into abutment against the shoulders 12 (position shown in dashed line on the figure). The pressure P thus prevailing in accumulator 1 has a predetermined value P min.

At this value of the operative pressure in the accumulator, the jacks 26 and 27 are no longer able to maintain valves 20 and 23 in their position shown in FIG. 1.

Repelling means 28 actuate valve 20 to a position of closure of pipe 19 and repelling means 29 actuate valve 23 to a position of opening, establishing communication between pipes 22 and 21.

The drilling mud, which is at a pressure P,, is supplied through pipes 25, 21 and 22 to the body 13 where it exerts on the upper face of piston 14 a strength which moves it downwardly in chamber 13 against the antagonistic action of spring 16.

During its downward motion, the piston 14 exerts on piston 10, through a push-rod 15, a strength of compression, on the fluid contained in tank 6. The piston 10 falls back in body 11 of tank 6 and presses back the hydraulic fluid into the accumulator 1, through pipe 8 and non-return valve 9.

When piston 10 is at its lowermost position (shown in mixed line) in tank 6, the pressure in the accumulator has reached the maximum value P max.

Then the jacks 26 and 27 of the valves 20 and 23, push back the valves to the position shown in FIG. 1, thereby producing the opening of the discharging pipe 19 and the interruption of the drilling mud feed to body 13 by closure of valve 23.

The spring 16, which has been previously compressed, is released, thereby allowing the piston 14 to rise while expelling the mud contained in the upper portion of chamber 13, through the discharge pipe 19.

The operation continues according to the cycle just indicated.

The pressure exerted by the external medium 17 is the hydrostatic pressure prevailing at the device immersion depth. It is thus obvious for the operation of the device, that the minimum pressure P min in the accumulator 1 is selected equal to or greater than the hydrostatic pressure P, at the considered depth.

S being the area of piston 14 on which is exerted the drilling mud pressure P,, and s being the section of piston 10, the maximum pressure P max in accumulator l is given by the relationship P max P, X S/S The respective sizes of pistons 10 and 14 will therefore be determined as a function of the mud pressure used and the selected value of pressure P max. Pressure P max will be chosen greater than pressure P min and will depend on the number of operations to be performed on the members without recharge of accumulator 1.

Of course there can be used as fluid a hydraulic fluid or a gas such as air.

From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention and, without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions, Consequently, such changes and modifications are properly, equitably and intended to be within the full range of equivalence of the following claims.

What 1 claim is:

1. A device for the storage and use of the power of a pressurized working fluid, comprising at least one tank containing said working fluid, means for pressurizing said working fluid in said tank and means for the storage and use of said pressurized working fluid connected to said tank, said means for pressurizing the working fluid being incorporated within said tank and being actuated by a pressurized auxiliary fluid.

2. A device for the storage and use of the power of a pressurized working fluid, associated with a submerged drilling well head, comprising at least one tank containing said working fluid, means for pressurizing said fluid in said tank and means for the storage and use of said pressurized fluid connected to said tank, said means for pressurizing the working fluid being actuated by a pressurized auxiliary fluid, said auxiliary fluid being the drilling fluid.

3. A device for the storage and use of the power of a pressurized working fluid, forming part of the equipment of a submerged drilling well head provided with drilling mud circulation lines, said device comprising at least one tank containing said working fluid, means for pressurizing said fluid in said tank and means for the storage and use of said pressurized fluid, connected to said tank, wherein said means for pressurizing the working fluid are connected to at least one drilling mud circulation line so as to be actuated by the pressure of said mud.

4. A device according to claim 3, wherein said means for pressurizing the working fluid are connected to at least one drilling mud feeding line.

5. A device according to claim 3, wherein said means for pressurizing the working fluid are connected to at least one return line for the drilling mud.

6. A device for the storage and use of the power of a pressurized working fluid, comprising at least one tank containing said working fluid, means for pressurizing said fluid in said tank and means for the storage and use of said pressurized fluid connected to said tank, said means for pressurizing the working fluid being actuated by a pressurized auxiliary fluid, the tank being of cylindrical shape and provided with a floating piston slidable in the tank body, the end parts of said tank being respectively connected to at least one accumulator of pressurized fluid and to fluid pressurizing means, adapted to move said floating piston so as to force the working fluid out from said tank towards said accumulater of pressurized fluid.

7. A device according to claim 6 wherein said fluid pressurizing means are formed of a piston, provided with a push-rod, slidable in a chamber surmounting said tank, said piston being displaced by the action of said auxiliary pressurized fluid and against the antagonistic action of repelling means, so as to produce, through the intermediary of the push-rod, the displacement of said floating piston in the direction resulting in the passages of the working fluid from the tank to the hydraulic accumulator, said chamber being connected to a line for the feed of auxiliary fluid and to a discharge line, said lines being controlled by at least one valve which obstructs said discharge line and opens said fluid feeding line in response to an inner pressure of the accumulator lower than a first predetermined value (P min) and which obstructs said auxiliary fluid feeding line and opens said discharge line in response to a pressure in the accumulator at last equal to a second predetermined value (P max). 

1. A device for the storage and use of the power of a pressurized working fluid, comprising at least one tank containing said working fluid, means for pressurizing said working fluid in said tank and means for the storage and use of said pressurized working fluid connected to said tank, said means for pressurizing the working fluid being incorporated within said tank and being actuated by a pressurized auxiliary fluid.
 2. A device for the storage and use of the power of a pressurized working fluid, associated with a submerged drilling well head, comprising at least one tank containing said working fluid, means for pressurizing said fluid in said tank and means for the storage and use of said pressurized fluid connected to said tank, said means for pressurizing the working fluid being actuated by a pressurized auxiliary fluid, said auxiliary fluid being the drilling fluid.
 3. A device for the storage and use of the power of a pressurized working fluid, forming part of the equipment of a submerged drilling well head provided with drilling mud circulation lines, said device comprising at least one tank containing said working fluid, means for pressurizing said fluid in said tank and means for the storage and use of said pressurized fluid, connected to said tank, wherein said means for pressurizing the working fluid are connected to at least one drilling mud circulation line so as to be actuated by the pressure of said mud.
 4. A device according to claim 3, wherein said means for pressurizing the working fluid are connected to at least one drilling mud feeding line.
 5. A device according to claim 3, wherein said means for pressurizing the working fluid are connected to at least one return line for the drilling mud.
 6. A device for the storage and use of the power of a pressurized working fluid, comprising at least one tank containing said working fluid, means for pressurizing said fluid in said tank and means for the storage and use of said pressurized fluid connected to said tank, said means for pressurizing the working fluid being actuated by a pressurized auxiliary fluid, the tank being of cylindrical shape and provided with a floating piston slidable in the tank body, the end parts of said tank being respectively connected to at least one accumulator of pressurized fluid and to fluid pressurizing means, adapted to move said floating piston so as to force the working fluid out from said tank towards said accumulator of pressurized fluid.
 7. A device according to claim 6 wherein said fluid pressurizing means are formed of a piston, provided with a push-rod, slidable in a chamber surmounting said tank, said piston being displaced by the action of said auxiliary pressurized fluid and against the antagonistic action of repelling means, so as to produce, through the intermediary of the push-rod, the displacement of said floating piston in the direction resulting in the passages of the working Fluid from the tank to the hydraulic accumulator, said chamber being connected to a line for the feed of auxiliary fluid and to a discharge line, said lines being controlled by at least one valve which obstructs said discharge line and opens said fluid feeding line in response to an inner pressure of the accumulator lower than a first predetermined value (P min) and which obstructs said auxiliary fluid feeding line and opens said discharge line in response to a pressure in the accumulator at last equal to a second predetermined value (P max). 